root/tags/1.3/wp-includes/link-template.php

<?php


function the_permalink() {
    echo apply_filters('the_permalink', get_permalink());
}


/**
 * Conditionally adds a trailing slash if the permalink structure
 * has a trailing slash, strips the trailing slash if not
 * @global object Uses $wp_rewrite
 * @param $string string a URL with or without a trailing slash
 * @param $type_of_url string the type of URL being considered (e.g. single, category, etc) for use in the filter
 * @return string
 */
function user_trailingslashit($string, $type_of_url = '') {
    global $wp_rewrite;
    if ( $wp_rewrite->use_trailing_slashes )
        $string = trailingslashit($string);
    else
        $string = untrailingslashit($string);

    // Note that $type_of_url can be one of following:
    // single, single_trackback, single_feed, single_paged, feed, category, page, year, month, day, paged
    $string = apply_filters('user_trailingslashit', $string, $type_of_url);
    return $string;
}


function permalink_anchor($mode = 'id') {
    global $post;
    switch ( strtolower($mode) ) {
        case 'title':
            $title = sanitize_title($post->post_title) . '-' . $id;
            echo '<a id="'.$title.'"></a>';
            break;
        case 'id':
        default:
            echo '<a id="post-' . $post->ID . '"></a>';
            break;
    }
}


function get_permalink($id = 0) {
    $rewritecode = array(
        '%year%',
        '%monthnum%',
        '%day%',
        '%hour%',
        '%minute%',
        '%second%',
        '%postname%',
        '%post_id%',
        '%category%',
        '%author%',
        '%pagename%'
    );

    $post = &get_post($id);

    if ( empty($post->ID) ) return FALSE;

    if ( $post->post_type == 'page' )
        return get_page_link($post->ID);
    elseif ($post->post_type == 'attachment')
        return get_attachment_link($post->ID);

    $permalink = get_option('permalink_structure');

    if ( '' != $permalink && !in_array($post->post_status, array('draft', 'pending')) ) {
        $unixtime = strtotime($post->post_date);

        $category = '';
        if (strpos($permalink, '%category%') !== false) {
            $cats = get_the_category($post->ID);
            if ( $cats )
                usort($cats, '_usort_terms_by_ID'); // order by ID
            $category = $cats[0]->slug;
            if ( $parent=$cats[0]->parent )
                $category = get_category_parents($parent, FALSE, '/', TRUE) . $category;
        }

        $authordata = get_userdata($post->post_author);
        $author = $authordata->user_nicename;
        $date = explode(" ",date('Y m d H i s', $unixtime));
        $rewritereplace =
        array(
            $date[0],
            $date[1],
            $date[2],
            $date[3],
            $date[4],
            $date[5],
            $post->post_name,
            $post->ID,
            $category,
            $author,
            $post->post_name,
        );
        $permalink = get_option('home') . str_replace($rewritecode, $rewritereplace, $permalink);
        $permalink = user_trailingslashit($permalink, 'single');
        return apply_filters('post_link', $permalink, $post);
    } else { // if they're not using the fancy permalink option
        $permalink = get_option('home') . '/?p=' . $post->ID;
        return apply_filters('post_link', $permalink, $post);
    }
}

// get permalink from post ID
function post_permalink($post_id = 0, $deprecated = '') {
    return get_permalink($post_id);
}

// Respects page_on_front.  Use this one.
function get_page_link($id = false) {
    global $post;

    $id = (int) $id;
    if ( !$id )
        $id = (int) $post->ID;

    if ( 'page' == get_option('show_on_front') && $id == get_option('page_on_front') )
        $link = get_option('home');
    else
        $link = _get_page_link( $id );

    return apply_filters('page_link', $link, $id);
}

// Ignores page_on_front.  Internal use only.
function _get_page_link( $id = false ) {
    global $post, $wp_rewrite;

    if ( !$id )
        $id = (int) $post->ID;

    $pagestruct = $wp_rewrite->get_page_permastruct();

    if ( '' != $pagestruct && 'draft' != $post->post_status ) {
        $link = get_page_uri($id);
        $link = str_replace('%pagename%', $link, $pagestruct);
        $link = get_option('home') . "/$link";
        $link = user_trailingslashit($link, 'page');
    } else {
        $link = get_option('home') . "/?page_id=$id";
    }

    return apply_filters( '_get_page_link', $link, $id );
}

function get_attachment_link($id = false) {
    global $post, $wp_rewrite;

    $link = false;

    if (! $id) {
        $id = (int) $post->ID;
    }

    $object = get_post($id);
    if ( $wp_rewrite->using_permalinks() && ($object->post_parent > 0) && ($object->post_parent != $id) ) {
        $parent = get_post($object->post_parent);
        if ( 'page' == $parent->post_type )
            $parentlink = _get_page_link( $object->post_parent ); // Ignores page_on_front
        else
            $parentlink = get_permalink( $object->post_parent );
        if (strpos($parentlink, '?') === false)
            $link = trailingslashit($parentlink) . $object->post_name . '/';
    }

    if (! $link ) {
        $link = get_bloginfo('url') . "/?attachment_id=$id";
    }

    return apply_filters('attachment_link', $link, $id);
}

function get_year_link($year) {
    global $wp_rewrite;
    if ( !$year )
        $year = gmdate('Y', time()+(get_option('gmt_offset') * 3600));
    $yearlink = $wp_rewrite->get_year_permastruct();
    if ( !empty($yearlink) ) {
        $yearlink = str_replace('%year%', $year, $yearlink);
        return apply_filters('year_link', get_option('home') . user_trailingslashit($yearlink, 'year'), $year);
    } else {
        return apply_filters('year_link', get_option('home') . '/?m=' . $year, $year);
    }
}

function get_month_link($year, $month) {
    global $wp_rewrite;
    if ( !$year )
        $year = gmdate('Y', time()+(get_option('gmt_offset') * 3600));
    if ( !$month )
        $month = gmdate('m', time()+(get_option('gmt_offset') * 3600));
    $monthlink = $wp_rewrite->get_month_permastruct();
    if ( !empty($monthlink) ) {
        $monthlink = str_replace('%year%', $year, $monthlink);
        $monthlink = str_replace('%monthnum%', zeroise(intval($month), 2), $monthlink);
        return apply_filters('month_link', get_option('home') . user_trailingslashit($monthlink, 'month'), $year, $month);
    } else {
        return apply_filters('month_link', get_option('home') . '/?m=' . $year . zeroise($month, 2), $year, $month);
    }
}

function get_day_link($year, $month, $day) {
    global $wp_rewrite;
    if ( !$year )
        $year = gmdate('Y', time()+(get_option('gmt_offset') * 3600));
    if ( !$month )
        $month = gmdate('m', time()+(get_option('gmt_offset') * 3600));
    if ( !$day )
        $day = gmdate('j', time()+(get_option('gmt_offset') * 3600));

    $daylink = $wp_rewrite->get_day_permastruct();
    if ( !empty($daylink) ) {
        $daylink = str_replace('%year%', $year, $daylink);
        $daylink = str_replace('%monthnum%', zeroise(intval($month), 2), $daylink);
        $daylink = str_replace('%day%', zeroise(intval($day), 2), $daylink);
        return apply_filters('day_link', get_option('home') . user_trailingslashit($daylink, 'day'), $year, $month, $day);
    } else {
        return apply_filters('day_link', get_option('home') . '/?m=' . $year . zeroise($month, 2) . zeroise($day, 2), $year, $month, $day);
    }
}

function get_feed_link($feed='rss2') {
    global $wp_rewrite;
    $do_perma = 0;
    $feed_url = get_option('siteurl');
    $comment_feed_url = $feed_url;

    $permalink = $wp_rewrite->get_feed_permastruct();
    if ( '' != $permalink ) {
        if ( false !== strpos($feed, 'comments_') ) {
            $feed = str_replace('comments_', '', $feed);
            $permalink = $wp_rewrite->get_comment_feed_permastruct();
        }

        if ( 'rss2' == $feed )
            $feed = '';

        $permalink = str_replace('%feed%', $feed, $permalink);
        $permalink = preg_replace('#/+#', '/', "/$permalink");
        $output =  get_option('home') . user_trailingslashit($permalink, 'feed');
    } else {
        if ( false !== strpos($feed, 'comments_') )
            $feed = str_replace('comments_', 'comments-', $feed);

        $output = get_option('home') . "/?feed={$feed}";
    }

    return apply_filters('feed_link', $output, $feed);
}

function get_post_comments_feed_link($post_id = '', $feed = 'rss2') {
    global $id;

    if ( empty($post_id) )
        $post_id = (int) $id;

    if ( '' != get_option('permalink_structure') ) {
        $url = trailingslashit( get_permalink($post_id) ) . 'feed';
        if ( 'rss2' != $feed )
            $url .= "/$feed";
        $url = user_trailingslashit($url, 'single_feed');
    } else {
        $type = get_post_field('post_type', $post_id);
        if ( 'page' == $type )
            $url = get_option('home') . "/?feed=$feed&amp;page_id=$post_id";
        else
            $url = get_option('home') . "/?feed=$feed&amp;p=$post_id";
    }

    return apply_filters('post_comments_feed_link', $url);
}

function get_edit_post_link( $id = 0 ) {
    $post = &get_post( $id );

    if ( $post->post_type == 'attachment' ) {
        return;
    } elseif ( $post->post_type == 'page' ) {
        if ( !current_user_can( 'edit_page', $post->ID ) )
            return;

        $file = 'page';
    } else {
        if ( !current_user_can( 'edit_post', $post->ID ) )
            return;

        $file = 'post';
    }

    return apply_filters( 'get_edit_post_link', get_bloginfo( 'wpurl' ) . '/wp-admin/' . $file . '.php?action=edit&amp;post=' . $post->ID, $post->ID );
}

function edit_post_link( $link = 'Edit This', $before = '', $after = '' ) {
    global $post;

    if ( $post->post_type == 'attachment' ) {
        return;
    } elseif ( $post->post_type == 'page' ) {
        if ( !current_user_can( 'edit_page', $post->ID ) )
            return;

        $file = 'page';
    } else {
        if ( !current_user_can( 'edit_post', $post->ID ) )
            return;

        $file = 'post';
    }

    $link = '<a href="' . get_edit_post_link( $post->ID ) . '" title="' . __( 'Edit post' ) . '">' . $link . '</a>';
    echo $before . apply_filters( 'edit_post_link', $link, $post->ID ) . $after;
}

function get_edit_comment_link( $comment_id = 0 ) {
    $comment = &get_comment( $comment_id );
    $post = &get_post( $comment->comment_post_ID );

    if ( $post->post_type == 'attachment' ) {
        return;
    } elseif ( $post->post_type == 'page' ) {
        if ( !current_user_can( 'edit_page', $post->ID ) )
            return;
    } else {
        if ( !current_user_can( 'edit_post', $post->ID ) )
            return;
    }

    $location = get_bloginfo( 'wpurl' ) . '/wp-admin/comment.php?action=editcomment&amp;c=' . $comment->comment_ID;
    return apply_filters( 'get_edit_comment_link', $location );
}

function edit_comment_link( $link = 'Edit This', $before = '', $after = '' ) {
    global $comment, $post;

    if ( $post->post_type == 'attachment' ) {
        return;
    } elseif ( $post->post_type == 'page' ) {
        if ( !current_user_can( 'edit_page', $post->ID ) )
            return;
    } else {
        if ( !current_user_can( 'edit_post', $post->ID ) )
            return;
    }

    $link = '<a href="' . get_edit_comment_link( $comment->comment_ID ) . '" title="' . __( 'Edit comment' ) . '">' . $link . '</a>';
    echo $before . apply_filters( 'edit_comment_link', $link, $comment->comment_ID ) . $after;
}

// Navigation links

function get_previous_post($in_same_cat = false, $excluded_categories = '') {
    global $post, $wpdb;

    if( empty($post) || !is_single() || is_attachment() )
        return null;

    $current_post_date = $post->post_date;

    $join = '';
    if ( $in_same_cat ) {
        $join = " INNER JOIN $wpdb->term_relationships AS tr ON p.ID = tr.object_id ";
        $cat_array = wp_get_object_terms($post->ID, 'category', 'fields=tt_ids');
        $join .= ' AND (tr.term_taxonomy_id = ' . intval($cat_array[0]);
        for ( $i = 1; $i < (count($cat_array)); $i++ ) {
            $join .= ' OR tr.term_taxonomy_id = ' . intval($cat_array[$i]);
        }
        $join .= ')';
    }

    $sql_exclude_cats = '';
    if ( !empty($excluded_categories) ) {
        $blah = explode(' and ', $excluded_categories);
        $posts_in_ex_cats = get_objects_in_term($blah, 'category');
        $posts_in_ex_cats_sql = 'AND p.ID NOT IN (' . implode($posts_in_ex_cats, ',') . ')';
    }

    $join  = apply_filters( 'get_previous_post_join', $join, $in_same_cat, $excluded_categories );
    $where = apply_filters( 'get_previous_post_where', "WHERE p.post_date < '$current_post_date' AND p.post_type = 'post' AND p.post_status = 'publish' $posts_in_ex_cats_sql", $in_same_cat, $excluded_categories );
    $sort  = apply_filters( 'get_previous_post_sort', 'ORDER BY p.post_date DESC LIMIT 1' );

    return @$wpdb->get_row("SELECT p.ID, p.post_title FROM $wpdb->posts AS p $join $where $sort");
}

function get_next_post($in_same_cat = false, $excluded_categories = '') {
    global $post, $wpdb;

    if( empty($post) || !is_single() || is_attachment() )
        return null;

    $current_post_date = $post->post_date;

    $join = '';
    if ( $in_same_cat ) {
        $join = " INNER JOIN $wpdb->term_relationships AS tr ON p.ID = tr.object_id ";
        $cat_array = wp_get_object_terms($post->ID, 'category', 'fields=tt_ids');
        $join .= ' AND (tr.term_taxonomy_id = ' . intval($cat_array[0]);
        for ( $i = 1; $i < (count($cat_array)); $i++ ) {
            $join .= ' OR tr.term_taxonomy_id = ' . intval($cat_array[$i]);
        }
        $join .= ')';
    }

    $sql_exclude_cats = '';
    if ( !empty($excluded_categories) ) {
        $blah = explode(' and ', $excluded_categories);
        $posts_in_ex_cats = get_objects_in_term($blah, 'category');
        $posts_in_ex_cats_sql = 'AND p.ID NOT IN (' . implode($posts_in_ex_cats, ',') . ')';
    }

    $join  = apply_filters( 'get_next_post_join', $join, $in_same_cat, $excluded_categories );
    $where = apply_filters( 'get_next_post_where', "WHERE p.post_date > '$current_post_date' AND p.post_type = 'post' AND p.post_status = 'publish' $posts_in_ex_cats_sql AND p.ID != $post->ID", $in_same_cat, $excluded_categories );
    $sort  = apply_filters( 'get_next_post_sort', 'ORDER BY p.post_date ASC LIMIT 1' );

    return @$wpdb->get_row("SELECT p.ID, p.post_title FROM $wpdb->posts AS p $join $where $sort");
}


function previous_post_link($format='&laquo; %link', $link='%title', $in_same_cat = false, $excluded_categories = '') {

    if ( is_attachment() )
        $post = & get_post($GLOBALS['post']->post_parent);
    else
        $post = get_previous_post($in_same_cat, $excluded_categories);

    if ( !$post )
        return;

    $title = $post->post_title;

    if ( empty($post->post_title) )
        $title = __('Previous Post');

    $title = apply_filters('the_title', $title, $post);
    $string = '<a href="'.get_permalink($post->ID).'">';
    $link = str_replace('%title', $title, $link);
    $link = $pre . $string . $link . '</a>';

    $format = str_replace('%link', $link, $format);